Bottle warmer



Jan. 12, 1954 A, B, JOHNSON I 2,666,127

Filed April 15, 1952 2 sheets-sheet 1 www ""/ INVENTOR. l

.. Z' fo/7250724 ||l I Jan. 12, 1954 A. B. JOHNSON BOTTLE WARMER 2 Sheets-Sheet 2 Filed April l5, 1952 cfa/27250)?,

Patented Jan. l2, 1954 UNITED sTATEs PATENT lFFICE BOTTLE WARMER Arne B. Johnson, Madison, Wi-s.

Application April 15, 1952, Serial No. 282,320 v (Crais- 40) 8 Claims.

. 1 The present invention relates to liquid 'conductor `heater structures, and more particularly to a container having a removable liquid heater adapted for use in warming nursing bottles or the like.

Liquid conductor heaters generally comprise a liquid container of insulating material having conducting electrodes in a portion thereof arranged tobe immersed in the contained liquid. A suitable electric current is applied to opposing pairs of the conductive electrodes to ca-use the electric current to be conducted from one electrodeto the otherthrough the conductive path established bythe contained liquid. The resistance of the conductive path causes the temperature of `the contained liquid to rise to a desired amount depending upon the variable factors such as theA applied potential, the area and spacing of therelectrodes, and the amount and kind of contained liquid.

.When using a liquid conductor heater structure as a nursing bottle warmer, the contained liquid is usually tap water. Tap water generally has a number of dissolved salts therein which, in theoperation of the liquid conductor heater, become deposited'ori the heater electrodes. The accumulation of deposited salts on the heater electrodes gradually forms an insulating coating which impairsthe eiiiciencyof the heater structure and reduces the current flow through the`conductive liquid to a value where insufficient heating action is obtained. It is therefore necessary to periodically replace or clean the electrode structures.

',Itfis an object ofthe present invention to provide an improved liquid. conductor heater structure in whichall of the'conductive elec-f trodes may be easily removed as aunit for cleaningor replacement.

' Another object of the invention'is to provide aA simpliiied assembly vof removable conductive electrodes for use in a liquidconductor heater structure.

Yet another object of the invention is to provide an improved arrangement for` automatical# ly r connecting a removably secured electrode structure. to the iixed electric power supply ter-Q'` minals of ay liquid v conductor heatercontainer When'the electrodeV structure is secured thereto;

A feature of the invention is the provision of a liquid heater including a liquid container of insulating material and a false A bottom assembly of .insulating material adapted tov be removably secured within the liquid container in a position overlying the bottom thereof, the rfalse bottom assembly including a pair of planar electrodes positioned generally parallel to the plane of the false bottom and spaced from each other.

Another feature of the invention is the ar rangement of a `pair of planar electrodes on the above-mentioned false bottom structure with the lower `electrode arranged to expose a portion of the upper electrode to which an electrical connection may be extended past the lower electrode.

Yet anotherl feature of the invention is the provision of a pair of resilient portions forautomatically establishing electrical connections between respective ones of a pair of electrodes carried by a removable false bottom structure and respective ones of a pair of fixed electric terminals on the inner bottom surface of a liquid conductor container in a manner to assure posi tive electrical connections. l f

A further feature of the invention is the novel arrangement for securing a conductive planar electrode to an insulating false bottom structure by means of an integral punched projection of the planar electrode, fthe projection being suitably retained inthe body of the false bottom structure.

Further objects, features and the attending advantages of the invention will be apparent from the Vfollowing speciiication' and drawings in which:

` Fig. 1 is an elevation View of the liquid conductor heater with a bottle in position to be warmed;

Fig. 2 is a top plan view;

Fig. 3 is a detail plan view of the underside of the removable false bottom and electrode structure;

Fig. 4 is a bottom view of the liquid container;

Fig; 5 is an exploded perspective view to show the assembly of the removable false bottom and liquid container; t

Fig. 6 is an enlarged fragmentary cross section on line E-S of Fig. 2; and

Figs. 7, 8 and 9 are fragmentary details of modified forms of the invention.

In practicing the invention, a liquid container of insulating material is provided with a pair of spaced electric power terminals on its inside bottom surface. A perforated false bottomr of insulating material is adapted to be removably secured on the inside bottom surface of the container. A pair of planar conductive electrodes having perforations therethrough are secured to i the underside of the false bottom to extend in a plane generally parallel to the false bottom in spaced positions with respect to each other. The lower electrode is arranged to expose a surface of the upper electrode to which an electrical connection may be extended past the lower electrode from the bottom surface of the container. The electrical connections are established by resilient connectors such as coil springs or depending projections of each electrode. The perforations in the false bottom `and planar electrodes enable the contained liquid to circulate between the electrodes for conducting an eleotric current therebetween. To assure the regisL try of the connections between the electrodes and terminals when the false bottom is assembled in the container, a plurality of projections are provided on the inner bottom surface of the container and they are adapted to be received in the plurality of peripheral `indentations of the false bottom thus determining the angular position `ofthe false bottom with respect to the bottom of the container and the electric terminals. In one form of the invention e'ach of the planar lelect'rodes vis secured to the false bottoni by upwardly extending integral projections that are embedded or Votherwise secured to the body of the false bottom.

For a more 'detailed description of the invention reference is made to 1 through 6 ofthe drawings. Tire noni-d container lo is formed of porcelain or other insulating material and is provided with a recessed portion I I on the underside of the bottom thereof. An electric line cord I2 is passed throughthe opening I3 in the sidewall of the container into the bottom recessed po n 'Il and respective conductors thereof oonriectdtothe electric terminals Il and l5. Terinal's IjllV and I5 are provided with upper contact surfaces I6 jan'd I1, respectively, which are received ,in `'suitable apertures on the upper Side of the bottoni portion of the container. A removable false bottom 'assembly ge orally 'shown at `|9 is varranged to be secured on the upper vsurface ofthe bottom portion of the container by means "o f the bolt 20 which may o' threaded into the pushing 2| that is scoured by the bolt 22 to the bottom surface of the con'- tz'ii'ier..r A j s nibre clearly shown in Figs.; 'ad 5 "ortho drawings, the removable false bottom I3, which is formed of insulating material similar to the material of the container In, is provided with a plurality of 'perforations 24 therethrough. A plurality of raised surfaces 2,5 are also provided and a nursing bottle such as "shown at 25 (Figl) may be hirestegd thereon for purposes o'f warming the bottle. The raised surfaces z serve to 'per mit the circulation of waterbeneath the bottle and vinto the e'rfo'r'ations 24 to fa central indentation 21 or the rolsooottom (rie. c).

"s 'more A l'e'arly J'shown in Figs. 3 and '6 of the drawing the underside of thefalse bottoni I9 nos scoured thorotoa pour ofo1anorjo1eotrooos 30 and ,3| formed 'of conductive material. such as stainless stoel the like. Afrire elconoces are positioned in planos generally parallel to the plaire of Vthe 'falso bottom ano-spaced from oooh other across the control indentation 2 The lower conductive 'electrode 3| is shaped `'and 'fp gt 'Stioooa in 'relation 'to th upper electrode 3 in a Vmanner'to expose a "portion 32 fof the upper oio'trooo. The oottomsorraoe Vof the container includes a projection 41 z which extendsupwardly past the fo1eo'troo 31.* `'rico projeotionjql an opiiing th'ori in 'which the ooi1 `spring 133 is positioned toooke oiotfiooioonnootionbetween the electric terminal I6 and the portion 32 of the electrode 38 when the removable false bottom I9 is secured to the upper bottom surface of the container I0. A similar coil spring 34 is effective to establish connection with a portion 35 of the lower electrode 3|. In such manner, electric power from the line cord I2 is applied across the opposing surfaces of the conducting electrodes 30 and 3|. It will be noted that each of the conductive electrodes is provided with a plurality of perforations such as shown at 36, through which liquid may circulate when the container is filled with a suitable liquid such as tap water or the like. It should be apparent that `when the line cord I2 is connected to a source of suitable electric power, an electric current will be conducted through the liquid between the electrodes 30 and 3| to thereby heat the liquid due to the resistance of the conductive path therein. As shown in Fi'g. 6, each of 'the planar 4'electrodes 3D and `3| are supported in a plane gorie orally parallel to the plane of the fal'sebttorn I9 by means of integral punched upstadl' projections 29 and 3'| which are folded over "at 38 'and 3!! in suitable recesses on the upper side of the false bottom I9. A waterproofhea't sistant and electrically insulating 'cement as shown at 4"0 and 4| colnpletefsthe assembly of the planar lelectrodes 30 and A3| to 'the fraise bottom I9.

In order to assure th `"`c`)'r'rc :t rgistr'y of the exposed 'terminal port-ions ft2, 35 'of "the electrodes f 3l),l 3|, respectively, lwitlr the coil springs 533, 534

and electric terminals 'I`6, IT. the f'al's 4bottolii 'It is provided 'with @plurality of peripheral iodontations azijn. suitable *upwardly extend lng projections 4 5441 'ar "arrangrl on the pp bottom surface of the container to b'e r'c'eivd in the recesses I2-54B and thereby locate the angular position of the false bottom I9 when secured within the container. i

modified for or the invention isshowo :in Fig. '7 wherein vthe V1planar "electrodos 3o 'and si are secured Itojthe false bottom I9 b y means of rivets 'stood 51. The electrode -an prorrata with fan integral downwardly extending `projec= tion sz fof establishing Contact with the electric terminal `lli fand, 'similarly, the electrode v3| provided "with an integral downwardly eictr'e`r-xi ine projection 53 ufor 'ostabushing contact with the kelett-:rio terminar l1 when the 'false bottoni I9 is Esecured within 'the container.

Fig. 8 shows `another'` modification 4oi 'the Line volition in 'which tho planar electrodos so. and al are secured "to the falso bottom as by moons ofthe rivets 5t 'and "5|, rn this/embodiment l'the coil Springs 33', 3'4 are pr'dvidd 'fOr fcsli'blisl'i' electrical connections to the respective 'elctic terminals rs, 11.4 `tho embodiment shown 'in rig. e thogfoiahor electrodes v30, 3"| Jare 'secured to 'the Ialsebottoin I9 by integral upstanding projections 213, "f3f1 fin o similar monitor to that 'proyioosiy Acostrinse in Fig. '6"of the drawings. In this arrangement. however. tho-elettrodotti is provided trio integral fdownwardlyeirtendir'ig projection L5` "and the lfomotioco V:n is orovidedfwitn the 'intgral downwardly extending "projection ta for estab'- iishirfg ieieotno'ai contact with the electric `torroina'isjlc lond in, respectively.

hotter in accordance "with theinvorition crudos @removable heater lu'frt which' 'sioriiofoom struotionfnd wiriohonoyibeiooonyropiaoooesem construction is such that unskilled persons can replace the unitcorrectly so that the heater will operate properly.

It should be understood that various other modifications may be made within the spirit of the invention and the Vscope of the appended claims.

I claim: l. In a liquid conductor heater of the type having a liquid container of insulating material and va pair of electric terminals in the base portion thereof connected to a line cord for connection with a source of electric current, the removable electrode assembly including in combination, a perforated false bottom of insulating material, a pair of planar electrodes of conductive materialy secured to said false bottom in spaced relation to each other and in planes generallyv parallel to the plane of the false bottom, said false bottom and said electrodes forming a unitary assembly for-easy replacement thereof, the lower one of said electrodes being arranged to expose a surface of the upper one of said electrodes, means independent of said terminals for removablysecuring said unitary assembly in said container, and resilient conducting means electrically interconnecting a respective one of said terminals with a respective one of said electrodes when said false bottom is secured within said container, one of said conducting means extending past the` lower of said electrodes into electrical contact with the exposed surface of the upper of said electrodes.

2. Ina liquid conductor heater of the type having a liquid container of insulating material and a pair of electric terminals in the base portion thereof connected` to a line cord for connection with a source of electric current, the removable electrode assembly including in combination, a perforated false bottom of insulating 4 material, a pair of planar electrodes of conductive material, each of said electrodes having an integral projection secured to said false bottom to mount said electrodes therefrom in spaced relation to each other and in planes generallyparallel to the plane of the false bottom, so that said false bottom and said electrodes form a unitary replaceable assembly, the lower one of said electrodes being arranged to expose a surface of the upper one of ysaid electrodes, spring means electrically interconnecting a respective one fof' said terminals with a respective one of saidV electrodes when said false bottom is secured within said container, one of said spring means extending past the lower of said electrodes into electrical contact with the exposed surface of the upper of said electrodes, and means independent of said spring means for securing said assembly to said base portion.

3. In a liquid conductor heater of the type having a liquid container of insulating material and a pair of electric terminals in the base portion thereof connected to a line cord for connection with a source of electric current, the removable electrode assembly including in combination, a perforated false bottom of insulating material, a pair of planar electrodes of conductive material, each of said electrodes having an integral projection secured to said false bottom to mount said electrodes therefrom in spaced relation to each other` in planes generally parallel to the plane of the false bottom, so that said false bottom and said electrodes form a unitary assembly, the lower one of said electrodes being arranged to expose a surface of the upper one of said electrodes, each of said electrodes having an integral downwardly extending projection for electrically interconnecting said electrode with a respective one of said terminals when said false bottom is secured within said container, said downwardly extending projection of said upper electrode extending past said lower electrode to establish contact with one of said terminals, and meansfindependent of said terminals for securingsaid electrode assembly to said base portion.

4. In a liquid conductor heater of the type having a liquid container of insulating material and a pair of electric terminals in the base portion thereof connected to a line cord for connection with a source of electric current, the removable electrode assembly including in combina-v tion, a removable perforated false bottom of insulating material, means to removably secure said false bottom within said container to the base portion thereof, a pair of planar electrodes of conductive'material secured to'said false bottom in spaced relation to each other inplanes generally parallel to the plane ofthe false bottom, the lower end of said electrodes being arranged to expose a surface of the upper one of said elec-trodes, and a pair of coil springs for electrically interconnecting a respective one of said terminals with a respective one of said electrodes when said false bottom is secured within said container, one of said coil springs extending past the lower of said electrodes to establish electrical contact between the exposed surface of the upper of said electrodes and one of said terminals. s

5. A liquid conductor heater including in combi1/lation, a liquid container of insulating material having a base portion with a pair of electric terminals secured therein adapted to be connected to a line cord for connectionrwithv a source 0f electric current, said container having a wall portion integral with said base portion, a removable electrode assembly including a perforated false bottom of insulating material, a pair of planar electrodes of conductive material, and means for securing said electrodes to said false bottom with said electrodes in spaced relation to each other and in planes-generally parallel to the plane of the false bottom, so that said false bottom and said electrodes form a unitary replaceable assembly, resilient conductor means for electrically interconnecting a respective one of said terminals with a respective one of said electrodes when said false bottom is secured Within said container on said base portion there-f of, the lower one of said electrodes being arranged to expose a surface of the upperfone of said electrodes, one of said conductor means eX- tending past the lower of said electrodes and making electrical contact with the exposed surface of the upper of said electrodes, and means independent of said terminals for securing said electrode assembly to said base portion.

6. A liquid conductor heater including in combination, a liquid container of insulating material having a base portion with a pair of electric terminals and a mounting stud secured therein, said terminals being adapted to lbe connected to a line cord for connection with a source of electric current, said container having a wall portion integral with said base portion, a removable electrode assembly including a perforated false bottom of insulating material and a pair of planar electrodes of conductive material, each of said electrodes having an integral projection secured to said false bottom to mount said electrodes therefrom in spaced relation to each other anuxin planes generally parallel. totheplone 4of. the false bottom s that Said ,false bottom and said electrodes form a unitary replaceable asf sembly. resilient conductor means for electrically interconnecting a respective one of said terminals with a respective one of said electrodes when said false bottom is secured within said container on said base portion thereof, the lower one of said electrodes being arranged to expose a surface of the upper one of said electrodes, one of said conductor means extending past the ,lower 0f Said electrodes and making electrical contact with the exposed surface of the upper of said electrodes, and mounting means cooperating with said mounting stud in said base portion for securing said electrode assembly to said base p0rtion.

'1. A liquid conductor heater including in combination, a. liquid container of insulating material having a base portion with a pair of electric terminals secured therein adapted to be connected to a line cord for connection with a source of electric current, said base portion having at least one upwardly extending projection thereon Within the container, a removable electrode assembly including a perforated false bottom of insulating material, said false bottom having a central indentation and at least one other indentation on the underside thereof adapted to fit about said projection on said base portion and thereby locate the angular position of the false bottom thereon, said assembly including a pair of perforated planar electrodes of conductive material secured to said false bottom in spaced relation to each other in planes generally parallel t0 the plane of the false bottom and extending across `said central indentation, the lower one of said electrodes being arranged to expose a sur.- face of the upper `one `oi said electrodes, means independent of said terminals for securing said electrode assembly to said base portion, and resilient conductor means for electrically lnterconnecting a respective one of said terminals with a respective one of said electrodes when said false bottom is secured within said container, one of said conductor means extending past the lower of said electrodes and making electrical contact with the exposed surface of the upper of said electrodes. i

8. A liquid conductor heater including in combination, a liquid container of insulating material having a `base portion with a pair of electric terminals at the sides thereof and a central mounting stud secured thereto, said electric terminals beine adapted tobe connected to e line oord for; connection with a sour-ceci electric current said base portion having an upwardlyextending tuen, lar projection about one of said terminals and having recesses therein above each of said terr.- minals., a removable electrode assembly including' a perforated false bottom of insulating materiah said false bottom having a central indentation on the underside thereoi and. a notch. at thefedge thereof adapted to fit about said proii'fotioli 9B. said base portion and thereby .locate the angular position of the false bottom thereon, said asseoir bly including a pair of perforated planar oleo,

trades of conductive material seoui'edftosaid false.

bottom in spaced relation to each other inv plenos generally parallel to the plane of the false bottone4 and extending across said central indenjgatiorxL each of said electrodes including an integral PlQf' jection thereon for securing the same to false bottom, the lower one of Said electrodeshan.l ing a notch aligned with said notch in said ,falseA bottom to expose a surface of the upper one :ot said electrodes, mounting means cooperating-withsaid mounting stud for securing said electrode` assembly to said base portion, and coil springs in said recesses for electrically interconnecting a'- respective one of said terminals with a `respective one of said electrodes when said false bottom is secured within said container, oneof said coil' springs extending through said tubular proj ection" past the lowerof said electrodes into electr-ical; contact with the exposed surface of the upper of said electrodes. o f 4 ARNE B. JLJIrIlrISON.` A

Referenties cned .in the me of minstens I UNITED STATES PATENTS f Germany Mar.` 30,114,925.' 

